Organic Chemistry Flashcards
What do hydrocarbons only contain
Hydrogen and carbon atoms
What bonds do alkanes have
C-C single bonds
What is the general formula for alkanes
CnH2n+2
What are alkanes
Saturated compounds - each carbon forms four covalent bonds
Chemical formula for methane
CH4
Formula for ethane
C2H6
Formula for propane
C3H8
Butane formula
C4H10
The shorter the carbon chain is…
The more volatile and less viscous it is and the lower the boiling point is
When does a complete combustion occur
When there is plenty of oxygen
Hydrocarbon + oxygen
Co2 + water
Crude oil is made over a ______ period of time
Long
Fractional distillation can be used to
Separate hydrocarbon fractions
What is crude oil
A mixture of lots of different hydrocarbons
How does fractional distillation work
Oil is heated then turned into gas
Hot at the bottom, cooler as you go up columns
Long hydrocarbons v high boiling points
Short hydrocarbons condense later on at the top
Petrol drains further up the fractioning column than diesel. What does this suggest about the boiling points of the hydrocarbons which make up petrol compared to diesel
Hydrocarbons in petrol have a lower boiling point than those in diesel
Alkenes
Unsaturated because they have a double carbon carbon bond
General formula for alkenes
CnH2n
Crude oil is a finite/infinite resource
Finite
What is the general formula of an alkane
Cn2n+2
What happens to bromine water when an alkene is added to it
It turns from orange to colourless
What method could be used to crack a long chain hydrocarbon
Mix the hydrocarbon vapour with steam and heat to a very high temperature
What technique is used to separate the components of crude oil
Fractional distillation
What happens to the carbon and hydrogen in a fuel when it’s burned
They are oxidised
True or false - cracking is used to turn long-chain hydrocarbons into short-chain hydrocarbons
True
Which alkane has the formula C4 H10
Butane
Balanced formula equation for the complete combustion of propane C3H8
C3H8 + 5O2 = 3CO2 + 4H20
